ENDOCRINE
Pituitary size increases up to threefold due to lactotroph hyperplasia and
hypertrophy, making it susceptible to ischemic injury (Sheehan syndrome)
from postpartum hypotension.
Adrenal gland size is unchanged, but production of cortisol increases two- to
threefold.
Thyroid size remains unchanged; thyroid binding globulin (TBG) increases,
resulting in increased total T 3 and T 4 (although free T 3 and free T 4 remain
unchanged).